Method of hair dyeing and hairdye set

ABSTRACT

The hair-coloring method of the invention is a method comprising coloring hair having virgin hair portions and already-colored hair portions, wherein (A) the virgin hair portions are colored with an oxidative hair-coloring agent (I) comprising an oxidative dye, ammonia and hydrogen peroxide and having an ammonia concentration of 0.2 to 3.0% by weight and a hydrogen peroxide concentration of 2.5 to 5.0% by weight, and (B) the already-colored hair portions are colored with an oxidative hair-coloring agent (II) comprising an oxidative dye, ammonia and hydrogen peroxide and having an ammonia concentration of 0.1 to 1.5% by weight and a hydrogen peroxide concentration of 0.01 to 2.0% by weight. The hair-coloring agent set of the invention is preferably used for the hair-coloring method. According to the invention, hair having virgin hair portions and already-colored hair portions can be colored in uniform color tone over the whole hair.

TECHNICAL FIELD

[0001] The present invention relates to a hair-coloring method. Moreparticularly, the invention relates to a method of uniformly coloringhair having virgin hair portions and already-colored hair portions and ahair-coloring agent set favorably used for the hair-coloring method.

BACKGROUND ART

[0002] Recently, people, who continuously have their hair colored haveincreased. Under such circumstances, coloring for obtaining uniformcolor over the whole hair or coloring for changing the hair to differentcolor has been requested with growth of hair.

[0003] When coloring for obtaining uniform color or coloring forchanging the hair to different color is performed, coexistence oforiginal hair having been not colored (referred to as “virgin hair”hereinafter) and hair having been already colored (referred to as%“already-colored hair” hereinafter) has to be taken into consideration.

[0004] For example, in case of hair having been colored with a generaloxidative hair-coloring agent, melanin has been destroyed and the dyehas been gradually washed away to discolor the hair in thealready-colored hair portions, and these portions have higher lightnessas compared with the virgin hair portions. Therefore, even if the samehair-coloring agent is used, the already-colored hair portions exhibitcolor tone of higher lightness as compared with the virgin hairportions, resulting in a problem that uniform coloring over the wholehair is impossible.

[0005] Under such circumstances as mentioned above, the presentinventors have earnestly studied, and as a result, they have found thatuniform color tone can be realized over the whole hair by the use ofdifferent hair-coloring agents, namely, oxidative hair-coloring agentseach of which contains ammonia and hydrogen peroxide in specificconcentrations, for the virgin hair portions and the already-coloredhair portions. Based on the finding, the present invention has beenaccomplished.

[0006] Accordingly, it is an object of the present invention to providea hair-coloring method by which hair having virgin hair portions andalready-colored hair portions can be colored in uniform color tone overthe whole hair, and a hair-coloring agent set which is favorably usedfor the hair-coloring method.

DISCLOSURE OF THE INVENTION

[0007] The hair-coloring method according to the present invention is ahair-coloring method comprising coloring hair having virgin hairportions and already-colored hair portions, wherein:

[0008] (A) the virgin hair portions are colored with an oxidativehair-coloring agent (I) comprising an oxidative dye, ammonia andhydrogen peroxide and having an ammonia concentration of 0.2 to 3.0% byweight and a hydrogen peroxide concentration of 2.5 to 5.0% by weight,and

[0009] (B) the already-colored hair portions are colored with anoxidative hair-coloring agent. (II) comprising an oxidative dye, ammoniaand hydrogen peroxide and having an ammonia concentration of 0.1 to 1.5%by weight and a hydrogen peroxide concentration of 0.01 to 2.0% byweight.

[0010] In the hair-coloring method of the invention, the oxidativehair-coloring agent (I) and the oxidative hair-coloring agent (II) needto satisfy at least one of the following conditions, preferably both ofthem, when white yak hair is colored with these hair-coloring agents for20 minutes at room temperature;

[0011] (i) the difference of lightness (Munsell lightness) in theMunsell color system between the hair colored with the oxidativehair-coloring agent (I) and the hair colored with the oxidativehair-coloring agent (II) is in the range of 0.2 to 3.0, and

[0012] (ii) the difference of chroma (Munsell chroma) in the Munsellcolor system between the hair colored with the oxidative hair-coloringagent (I) and the hair colored with the oxidative hair-coloring agent(II) is in the range of 0.05 to 5.0.

[0013] The hair-coloring agent set according to the present inventioncomprises:

[0014] (A) a hair-coloring agent for virgin hair portions (an oxidativehair-coloring agent (I)), comprising an oxidative dye., ammonia andhydrogen peroxide and having an ammonia concentration of 0.2 to 3.0% byweight and a hydrogen peroxide concentration of 2.5 to 5.0% by weight,and

[0015] (B) a hair-coloring agent for already-colored hair portions (anoxidative hair-coloring agent (II)), comprising an oxidative dye,ammonia and hydrogen peroxide and having an ammonia concentration of 0.1to 1.5% by weight and a hydrogen peroxide concentration of 0.01 to 2.0%by weight.

[0016] In the hair-coloring agent set of the invention, thehair-coloring agent for virgin hair portions and the hair-coloring agentfor already-colored hair portions need to satisfy at least one of thefollowing conditions, preferably both of them, when white yak hair iscolored with these hair-coloring agents for 20 minutes at roomtemperature;

[0017] (i) the difference of lightness (Munsell lightness) in theMunsell color system between the hair colored with the hair-coloringagent for virgin hair portions and the hair colored with thehair-coloring agent for already-colored hair portions is in the range of0.2 to 3.0, and

[0018] (ii) the difference of chroma (Munsell chroma) in the Munsellcolor system between the hair colored with the hair-coloring agent forvirgin hair portions and the hair colored with the hair-coloring agentfor already-colored hair portions is in the range of 0.05 to 5.0.

[0019] According to the present invention, when the virgin hair portionsobtained by coloring with the oxidative hair-coloring agent (I) and thealready-colored hair portions obtained by coloring with the oxidativehair-coloring agent′ (II) are compared, these portions have almost the′same hue, lightness and chroma.

BEST MODE FOR CARRYING OUT THE INVENTION

[0020] The hair-coloring method according to the invention and thehair-coloring agent set preferably used for the hair-coloring method aredescribed in detail hereinafter.

[0021] The hair-coloring method according to the invention is ahair-coloring method comprising coloring hair having virgin hairportions and already-colored hair portions, wherein:

[0022] (A) an oxidative hair-coloring agent (I) containing an oxidativedye and further containing ammonia and hydrogen peroxide in specificconcentrations is applied to the virgin hair portions to color it, and

[0023] (B) an oxidative hair-coloring agent (II) containing an oxidativedye and further containing ammonia and hydrogen peroxide in specificconcentrations is applied to the already-colored hair portions to colorit,

[0024] whereby the whole hair is colored in uniform color tone.

[0025] The hair-coloring agent set according to the 0.20 inventioncomprises:

[0026] (A) a hair-coloring agent for virgin hair portions (an oxidativehair-coloring agent (I))., containing an oxidative dye and furthercontaining ammonia and hydrogen peroxide in specific concentrations, and

[0027] (B) a hair-coloring agent for already-colored hair portions (anoxidative hair-coloring agent (II)), containing an oxidative dye andfurther containing ammonia and hydrogen peroxide in specificconcentrations.

Hair-Coloring Agent Set

[0028] Oxidative Hair-Coloring Agent (I) and Oxidative Hair-ColoringAgent (II)

[0029] First, the oxidative hair-coloring agent (I) and the oxidativehair-coloring agent (II) for use in the invention are described.

[0030] The oxidative hair-coloring agent (I) used for the virgin hairportions of hair, i.e., hair-coloring agent for virgin hair portions,comprises an oxidative dye, ammonia and hydrogen peroxide. In theoxidative hair-coloring agent (I), the ammonia concentration is in therange of 0.2 to 3.0% by weight, preferably 0.4 to 2.0% by weight, morepreferably 0.5 to 1.7% by weight, and the hydrogen peroxideconcentration is in the range of 2.5 to 5.0% by weight, preferably 2.8to 4.5% by weight, more preferably 3.0 to 4.0% by weight.

[0031] The oxidative hair-coloring agent (II) used for thealready-colored hair portions of hair, i.e., hair-coloring agent foralready-colored hair portions, comprises an oxidative dye, ammonia andhydrogen peroxide. In the oxidative hair-coloring agent (II), theammonia concentration is in the range of 0.1 to 1.5% by weight,preferably 0.25 to 1.0% by weight, more preferably 0.4 to 0.7% byweight, and the hydrogen peroxide concentration is in the range of 0.01to 2.0% by weight, preferably 0.5 to 1.8% by weight, more preferably 1.0to 1.6% by weight.

[0032] For preparing the oxidative hair-coloring agents containingammonia and hydrogen peroxide in the above concentrations, ammonia andhydrogen peroxide are preferably used in the form of ammonia water andhydrogen peroxide water, respectively, from the viewpoint of easyhandling.

[0033] By incorporating ammonia and hydrogen peroxide in the oxidativehair-coloring agents (I) and (II), i.e., hair coloring agent for virginhair portions and hair-coloring agent for already-colored hair portionsin the above concentrations, the color tone of the virgin hair portionsand that of the already colored-hair portions after coloring can be madeuniform. In the vicinity of boundaries between the virgin hair portionsand the already-colored hair portions, there has been conventionallyobserved a phenomenon that different hair-coloring agents are mixed toform a zone of different color tone. By the use of the hair-coloringagent set of the invention, however, such boundary portions can be alsocolored in the same uniform color tone as that of other portions, andconsequently, the whole hair can be colored in uniform color tone.

[0034] That is to say, because the oxidative hair-coloring agent (I)that is the hair-coloring agent for virgin hair portions is used for thevirgin hair portions, it needs to bleach hair to increase lightness ofthe hair, while because the oxidative hair-coloring agent (II) that isthe hair-coloring agent for already-colored hair portions is used forthe already-colored hair portions, it maintains the existing conditionwithout further increasing lightness of hair, whereby both of thelightness of the virgin hair portions and the lightness of thealready-colored hair portions can be controlled, and besides the chromaand the hue of both portions can be controlled to almost the same levelby the action of the oxidative dye, etc.

[0035] Manufactured goods of the oxidative hair-coloring agents (I) and(II) preferably consist of a first agent containing, as mainingredients, an oxidative dye, ammonia, etc. and a second agentcontaining, as main ingredients, hydrogen peroxide, etc., and in the useof a hair-coloring agent set of such two-pack type, both of the agents(first agent and second agent) have only to be mixed. There is nospecific limitation on the form of the first agent and the second agent,and for example, they are preferably used in the form of a liquid or acream.

[0036] Next, the two-pack type is described.

[0037] First Agent

[0038] The first agent in each of the oxidative hair-coloring agents (I)and (II) contains an oxidative dye, ammonia and pure water as mainingredients.

[0039] The oxidative dye is not specifically restricted, and oxidativedyes publicly known are employable. The oxidative dye generally consistsof a dye precursor and if necessary a coupler.

[0040] Examples of the dye precursors include p-phenylenediamine,p-aminophenol, p-methylaminophenol, p-toluenediamine(toluene-2,5-diamine), o-phenylenediamine, o-aminophenol,toluene-3,4-diamine, N,N-bis (hydroxyethyl)-p-phenylenediamine,2-(hydroxyethyl)-p-phenylenediamine, N-phenyl-p-phenylenediamine,4,4′-diaminodiphenylamine, 2-chloro-p-phenylenediamine,N,N-dimethyl-p-phenylenediamine, 2, 6-dichloro-p-phenylenediamine,p-aminophenylsulfamic acid and 2,5-diaminopyridine.

[0041] The above dye-precursors may be used singly or in appropriatecombination depending upon the color tone intended to be obtained bycoloring of hair.

[0042] Examples of the couplers include meta-components, such asm-phenylenediamine and m-aminophenol, polyphenols, such as resorcin,pyrogallol, catechol, 1,2,4-benzenetriol and hydroquinone,p-amino-o-cresol (4-amino-o-cresol), 5-amino-o-cresol,2,4-diaminophenol, toluene-3,4-diamine toluene-2,4-diamine,2,6-diaminopyridine, 3,3′-iminodiphenol, 1,5-dihydroxynaphthalene,diphenylamine, phloroglucin, 2.4-diaminophenoxyethanol, gallic acid,tannic acid, ethyl gallate, methyl gallate, propyl gallate, Japanesegall, 1-methoxy-2-amino-4-(2-hydroxyethyl)aminobenzene and5-(2-hydroxyethylamino)-2-methylphenl.

[0043] The p-aminophenol and the o-aminophenol can be used not only as adye precursor but also as a coupler. The above couplers may be usedsingly or in appropriate combination depending upon the color toneintended to be obtained by coloring of hair.

[0044] Further, direct dyes, e.g., nitro dyes such asnitro-p-phenylenediamine, may be used when needed.

[0045] In the present invention, the dye is used in the first agent inan amount of about 0.01 to 3.0% by weight based on 100% by weight of thewhole of the first agent.

[0046] As the dye for use in the oxidative hair-coloring agent-(I) usedfor the virgin hair portions, namely, the hair-coloring agent for virginhair portions, a dye, which is expected to develop color of higherlightness and higher chroma (vivid) of the same color type as comparedwith the dye for use in the oxidative hair-coloring agent (II), namely,the hair-coloring agent for already-colored hair portions, is preferablyselected from the above dyes.

[0047] The oxidative hair-coloring agent (I) needs to increase lightnessand chroma of hair because it is used for the virgin hair portions, andthe dye used for the agent is required to satisfy the above conditions.

[0048] On the other hand, as the dye for use in the oxidativehair-coloring agent (II) used for the already-colored hair portions, adye, which is expected to develop color of lower lightness and lowerchroma. (dim) of the same color type as compared with the dye for use inthe oxidative hair-coloring agent (I), is preferably selected from theabove dyes. That is to say, the oxidative hair-coloring agent (II) needsto decrease lightness and chroma of hair because it is used for thealready-colored hair portions, and the dye used for the agent isrequired to satisfy the above conditions.

[0049] More specifically, it is preferable to select such a dye that theoxidative hair-coloring agents (I) and (II), each of which is preparedby mixing the first agent consisting of the dye and other ingredientssuch as ammonia and pure water with the later-described second agent ina given mixing ratio, satisfy at least one of the following conditions(i) and (ii).

[0050] When white yak hair is colored with the oxidative hair-coloringagent (I) and the oxidative hair-coloring agent (II) for 20 minutes atroom temperature,

[0051] (i) the difference of lightness (Munsell lightness) in theMunsell color system between the hair colored with the oxidativehair-coloring agent (I), and the hair colored with the oxidativehair-coloring agent (II) is in the range of usually 0.2 to 3.0,preferably 0.6 to 2.2, and

[0052] (ii) the difference of chroma (Munsell chroma) in the Munsellcolor system between the hair colored with the oxidative hair-coloringagent (I) and the hair colored with the oxidative hair-coloring agent(II) is in the range of usually 0.05 to 5.0, preferably 0.1 to 3.0.

[0053] It is more preferable that when white yak hair is colored withthe oxidative hair-coloring agent (I) and the oxidative hair-coloringagent (II) for 20 minutes at room temperature, the hue (Munsell hue), inthe Munsell color system, of the hair colored with the oxidativehair-coloring agent (I) and the hue (Munsell hue), in the Munsell colorsystem, of the hair colored with the oxidative hair-coloring agent (II)are on almost the same level. The term “almost the same level” usedherein means that the hues (Munsell hues) of both the hair are of thesame color type, namely, warm color type or cool color type, anddesirably means that they agree with each other regarding the 10 hues(R, YR, Y, GY, G, BG, B, PB, P, RP).

[0054] In the first agent, ammonia water of, for example, 28 wt %concentration can be used in an amount of 6 to 12% by weight based on100% by weight of the whole of the first agent. In the use of ammoniawater, the desired ammonia concentration has only to be obtained whenthe oxidative hair-coloring agent (I) or (II) is prepared byappropriately mixing the first agent with the second agent.

[0055] Examples of the pure water preferably used in the inventioninclude ion-exchanged water and distilled water. The amount of the purewater used is not specifically restricted and has only to be such anamount that the ingredients used for the first agent can be sufficientlydissolved-or dispersed.

[0056] To the first agent, additives, such as surface active agent,stabilizer and oil ingredient, can be added when needed. These additivesare not specifically restricted, and those publicly known areemployable.

[0057] Second Agent

[0058] The second agent in each of the oxidative hair-coloring agents(I) and (II) contains hydrogen peroxide and pure water as mainingredients.

[0059] In the second agent, hydrogen peroxide water of, for example, 35wt % concentration can be used in an amount of 13 to 17% by weight basedon 100% by weight of the whole of the second agent. In the use ofhydrogen peroxide water, the desired hydrogen peroxide concentration hasonly to be obtained when the oxidative hair-coloring agent (I) or (II)is prepared by appropriately mixing the first agent with the secondagent.

[0060] The type, amount, etc. of the pure water employable for thesecond agent are the same as those previously described with respect tothe first agent.

[0061] To the second agent, additives, such as surface active agent, oilingredient, chelating agent and pH adjustor, can be added when needed.These additives are not specifically restricted, and those publiclyknown are employable.

[0062] The oxidative hair-coloring agent (I) is preferably prepared bymixing the first agent with the second agent immediately before coloringof hair (application to hair), and pH of the oxidative hair-coloringagent (I) thus prepared is preferably in the range of 9.5 to 10.5.

[0063] Also, the oxidative hair-coloring agent (II) is preferablyprepared by mixing the first agent with the second agent immediatelybefore coloring of hair (application to hair), and pH of the oxidativehair-coloring agent (II) thus prepared is preferably in the range of 9.3to 10.1.

[0064] In the present invention, a set of the oxidative hair-coloringagent (I) as the hair-coloring agent for virgin hair portions and theoxidative hair-coloring agent (II) as the hair-coloring agent foralready-colored hair portions is provided. By providing such a set,excellent long-term storage properties are exhibited. Further, eachagent (first agent or second agent) can be replenished when needed, andthis is convenient and economical. Moreover, because necessary agentsare provided as a set, erroneous use does not brought about, and this isadvantageous in the practical use. In addition, desired and prescribedeffects are always exerted.

Hair-Coloring Method

[0065] Next, the hair-coloring method of the invention is described indetail.

[0066] According to the present invention, in the coloring of hairhaving virgin hair portions and already-colored hair portions, (A) theoxidative hair-coloring agent (I) obtained as above is applied to thevirgin hair portions to color it, and (B) the oxidative hair-coloringagent (II) obtained as above is applied to the already-colored hairportions to color it, whereby the whole hair is colored in uniform colortone.

[0067] The virgin hair portions obtained by coloring with the oxidativehair-coloring agent (I) and the already-colored hair portions obtainedby coloring with the oxidative hair-coloring agent (II) preferably havealmost the same hue, lightness and chroma.

[0068] Although the hue, the lightness and the chroma may be confirmedby visual observation, it is desirable that the difference of lightness(Munsell lightness) in the Munsell color system between the virgin hairportions and the already-colored hair portions after coloring is in therange of usually 0.01 to 1.0, preferably 0.05 to 0.5; the difference ofchroma (Munsell chroma) in the Munsell color system between the virginhair portions and the already-colored hair portions after coloring is inthe range of usually 0.01 to 1.0, preferably 0.05 to 0.5; and the hues(Munsell hues) of both the portions agree with each other regarding the10 hues (R, YR, Y, GY, G, BG, B, PB, P, RP).

[0069] In general, the color tone obtained by coloring greatly dependsupon degree of color development due to the oxidative dye itself anddegree of bleaching of hair. Especially in case of hair of Japanese, theobject of coloring is black hair containing a large amount of melanin,and therefore, the color tone actually obtained by coloring greatlyvaries depending upon degree of bleaching.

[0070] In the coloring of hair by the use of the oxidative hair-coloringagent, ammonia has not only a function of swelling hair to acceleratepermeation of dye but also a function of accelerating decomposition ofhydrogen peroxide to generate oxygen. Owing to the thus generatedoxygen, the melanin in the hair is destroyed, whereby the hair isbleached and the oxidative dye develops color.

[0071] As described above, there is a close relationship between ammoniaand hydrogen peroxide in the oxidative hair-coloring agent, and byvirtue of their mutual action, coloring of hair is promoted.

[0072] In the present invention, the different oxidative hair-coloringagents (I) and (II) obtained by adding ammonia and hydrogen peroxide inspecific amounts as described above were used in combination for thevirgin hair portions and the already-colored hair portions, whereby thedegree of bleaching of hair due to each oxidative hair-coloring agentand the tone of color developed by the oxidative dye are strictlycontrolled, and consequently, the virgin hair portions and thealready-colored hair portions can be colored in uniform color tone.Moreover, the boundary portions between the virgin hair portions and thealready-colored hair portions can also have the same uniform color toneas that of other portions. That is to say, according to the presentinvention, a problem that the oxidative hair-coloring agent applied tothe virgin hair portions and the oxidative hair-coloring agent appliedto the already-colored hair portions are mixed in the boundary portionsbetween the virgin hair portions and the already-colored hair portionsto form a zone of different color from that of other portions can besolved, and such boundary portions can also be colored in the sameuniform color tone as that of other portions.

EFFECT OF THE INVENTION

[0073] According to the present invention, hair having virgin hairportions and already-colored hair portions can be colored in uniformcolor tone over the whole hair.

[0074] According to the hair-coloring agent set of the invention,coloring of hair can be efficiently carried out.

EXAMPLE

[0075] The present invention is further described with reference to thefollowing examples, but it should be construed that the invention is inno way limited to those examples.

[0076] Hair colored with oxidative hair-coloring agents prepared in thefollowing examples and comparative examples was measured on the hue(Munsell hue), lightness (Munsell lightness) and chroma (Munsell chroma)in the Munsell color system in accordance with the methods describedbelow.

[0077] Measuring Method Using Color-Difference Meter

[0078] About 1.5 g of a bundle of commercially available white yak hairwas prepared, and to the bundle of hair, oxidative hair-coloring agents(I)-1 to (I)-7, (II)-1 to (II)-7, C1 and C2 obtained in the followingexamples and comparative examples were each applied in an appropriateamount, followed by allowing the bundle of hair to stand for 20 minutesat room temperature, to color the hair. The bundle of the colored yakhair was cleaned with shampoo and a rinsing liquid and then dried in aconventional manner.

[0079] Thereafter, the bundle of the colored yak hair was measured onthe aforesaid items using a color-difference meter CR-200 type(manufactured by Minolta Co., Ltd., measuring light: standard light D65,color temperature: 6504K) and setting the color system mode to MUNSELLmode.

[0080] More specifically, the bundle of the colored hair was placed on ablack board, and a light receptor of the color-difference meter waspushed against the bundle of the hair to measure hue, lightness andchroma in the Munsell color system. Then, this measurement was carriedout twice with changing the measuring position of the bundle of thehair, and an average value of the measurements of three times wascalculated.

[0081] The results are set forth in Table 4.

Example 1 Preparation of First Agent

[0082] In accordance with the compounding proportions shown in Table 1,a first agent for virgin hair portions and a first agent foralready-colored hair portions were prepared in the following manner.

[0083] First, cetanol, liquid paraffin, polyoxyethylene stearyl ether,stearyltrimethylammonium chloride and polyethylene glycol were placed ina reactor vessel equipped with a stirring device and heated at 75° C. togive a solution. With stirring the solution; a solution obtained bydissolving paraphenylenediamine, paraaminophenol, paraaminoorthocresoland sodium sulfite in pure water at 75° C. was gradually added, thenthey were cooled to 30° C. with stirring, and 28 wt % ammonia water wasadded, to obtain creamy first agents.

Preparation of Second Agent

[0084] In accordance with the compounding proportions shown in Table 2and using 35 wt % hydrogen peroxide water, a creamy second agent havinga hydrogen peroxide content of 6% by weight and a creamy second agenthaving a hydrogen peroxide content of 3% by weight were prepared in aconventional manner.

Coloring and Evaluation

[0085] Hair, which had been subjected to coloring of brown type abouttwo months before and in which the virgin hair portions were normalblack hair of Japanese and the already-colored hair portions hadconsiderably high lightness, was subjected to coloring.

[0086] First, to the virgin hair portions, an oxidative hair-coloringagent (I)-1 obtained by mixing the first agent for virgin hair portionswith the second agent for virgin hair portions (hydrogen peroxidecontent: 6% by weight) in a mixing ratio of 1:2 (by weight) was applied.The oxidative hair-coloring agent (I)-1 had an ammonia concentration of1.0% by weight, a hydrogen peroxide concentration of 3.8% by weight andpH of 10.3.

[0087] Immediately after the application to the virgin hair portions, tothe already-colored hair portions, an oxidative hair-coloring agent(II)-1 obtained by mixing the first agent for already-colored hairportions with the second agent for already-colored hair portions(hydrogen peroxide content: 3% by weight) in a mixing 5′ ratio of 1:1(by weight) was applied, followed by allowing the hair to stand for 15minutes at room temperature. The oxidative hair-coloring agent (II)-1had an ammonia concentration of 0.6% by weight, a hydrogen peroxideconcentration of 1.6% by weight and pH 0.10 of 9.6.

[0088] Thereafter, the hair was sufficiently cleaned with shampoo andthen rinsed in a conventional manner.

[0089] As a result of evaluation of the colored hair by visualobservation, the virgin hair portions and the already-colored hairportions were uniformly colored, and even in the boundary portions, thesame uniform color tone as in other portions could be attained.

[0090] The results are set forth in Table 5.

Example 2 Preparation of First Agent

[0091] A first agent for virgin hair portions and a first agent foralready-colored hair portions were prepared in the same manner as inExample 1, except that the compounding proportions-were changed as shownin Table 1.

Preparation of Second Agent

[0092] In accordance with the compounding proportions shown in Table 2and using 35′ wt % hydrogen peroxide water, a creamy second agent havinga hydrogen peroxide content of 6% by weight and a creamy second agenthaving a hydrogen peroxide content of 3% by weight were prepared in aconventional manner.

Coloring and Evaluation

[0093] Hair, which had been subjected to coloring of brown type abouttwo months before and in which the virgin hair portions were normalblack hair of Japanese, the black virgin hair portions had a length ofabout 2 cm and the already-colored hair portions had considerably highlightness, was subjected to coloring so as to give color tone of naturaltype.

[0094] First, to the virgin hair portions, an oxidative hair-coloringagent (I)-2 obtained by mixing the first agent for virgin hair portionswith the second agent for virgin hair portions (hydrogen peroxidecontent: 6% by weight) in a mixing ratio of 1:2 (by weight) was applied.The oxidative hair-coloring agent-(I)-2 had an ammonia concentration of0.84% by weight, a hydrogen peroxide concentration of 3.8% by weight andpH of 10.2.

[0095] Immediately after the application to the virgin hair portions, tothe already-colored hair portions, an oxidative hair-coloring agent(II)-2 obtained by mixing the first agent for already-colored hairportions with the second agent for already-colored hair portions(hydrogen peroxide content: 3% by weight) in a mixing ratio of 1:1 (byweight) was applied, followed by allowing the hair to stand for 15minutes at room temperature. The oxidative hair-coloring agent (II)-2had an ammonia concentration of 0.56% by weight, a hydrogen peroxideconcentration of 1.6% by weight and pH of 10.0.

[0096] Thereafter, the hair was sufficiently cleaned with shampoo andthen rinsed in a conventional manner.

[0097] As a result of evaluation of the colored hair by visualobservation, the virgin hair portions and the already-colored hairportions were uniformly colored in color tone of natural type, and evenin the boundary portions, the same uniform color tone as in otherportions could be attained.

[0098] The results are set forth in Table 5.

Example 3 Preparation of First Agent

[0099] A first agent for virgin hair portions and a first agent foralready-colored hair portions were prepared in the same manner as inExample 1, except that the compounding proportions were changed as shownin Table 1.

Preparation of Second Agent

[0100] In accordance with the compounding proportions shown in Table 2and using 35 wt % hydrogen peroxide water, a creamy second agent havinga hydrogen peroxide content of 6% by weight and a creamy second agenthaving a hydrogen peroxide content of 3% by weight were prepared in aconventional manner.

Coloring and Evaluation

[0101] Hair, in which the virgin hair portions and the already-coloredhair portions were in the same states as those of the hair in Example 2,was subjected to coloring so as to give color tone of natural type.

[0102] First, to the virgin hair portions, an oxidative hair-coloringagent (I)-3 obtained by mixing the first agent for virgin hair portionswith the second agent for virgin hair portions (hydrogen peroxidecontent: 6% by weight) in a mixing ratio of 1:1 (by weight) was applied.The oxidative hair-coloring agent (I)-3 had an ammonia: concentration of1.26% by weight, a hydrogen peroxide concentration of 2.90% by weightand pH of 10.2.

[0103] After 5 minutes from the application to the virgin hair portions,to the already-colored hair portions, an oxidative hair-coloring agent(II)-3 obtained by mixing the first agent for already-colored hairportions with the second agent for already-colored hair portions(hydrogen peroxide content: 3% by weight) in a mixing ratio of 1:1 (byweight) was applied, followed by allowing the hair to stand for 15minutes at room temperature. The oxidative hair-coloring agent (II)-3had an ammonia concentration of 0.56% by weight, a hydrogen peroxideconcentration of 1.6% by weight and pH of 10.0.

[0104] Thereafter, the: hair was sufficiently cleaned with shampoo andthen rinsed in a conventional manner.

[0105] As a result of evaluation of the colored hair by visualobservation, the virgin hair portions and the already-colored hairportions were uniformly colored in color tone of natural type, and evenin the boundary portions, the same uniform color tone as in otherportions could be attained.

[0106] The results are set forth in Table 5.

Example 4 Preparation of First Agent

[0107] A first-agent for virgin hair portions and a first agent foralready-colored hair portions were prepared in the same manner as inExample 1, except that the compounding proportions were changed as shownin Table 1.

Preparation of Second Agent

[0108] In accordance with the compounding proportions shown in Table 2and using 35 wt % hydrogen peroxide water, a creamy second agent havinga hydrogen peroxide content of 6% by weight and a creamy second agenthaving a hydrogen peroxide content of 3% by weight were prepared in aconventional manner.

Coloring and Evaluation

[0109] Hair, in which the virgin hair portions and the already-coloredhair portions were in the same states as those of the hair in Example 2,was subjected to coloring so as to give color tone of natural type.

[0110] First, to the virgin hair portions, an oxidative hair-coloringagent (I)-4 obtained by mixing the first agent for virgin hair portionswith the second agent for virgin hair portions (hydrogen peroxidecontent: 6% by weight) in a mixing ratio of 1:1 (by weight) was applied.The oxidative hair-coloring agent (I)-4 had an ammonia concentration of0.84% by weight, a hydrogen peroxide concentration of 2.8% by weight andpH of 10.1.

[0111] Immediately after the application to the virgin hair portions, tothe already-colored hair portions, an oxidative hair-coloring agent(II)-4 obtained by mixing the first agent for already-colored hairportions wit the second agent for already-colored hair portions(hydrogen peroxide content: 3% by weight) in a mixing ratio of 1:1 (byweight) was applied, followed by allowing the hair to stand for 15minutes at room temperature. The oxidative hair-coloring agent (II)-4had an ammonia concentration of 0.1% by weight, a hydrogen peroxideconcentration of 1.6% by weight and pH of 9.6.

[0112] Thereafter, the hair was sufficiently cleaned with shampoo andthen rinsed in a conventional manner.

[0113] As a result of evaluation of the colored hair by visualobservation, the boundary portions between the virgin hair portions andthe already-colored hair portions became a light zone. The virgin hairportions did not seem to have hue of natural type and were slightlydarker as compared with the already-colored hair portions. Thealready-colored hair portions were slightly lighter as compared with thevirgin hair portions and had poor uniformity of finished color.

[0114] The results are set forth in Table 5.

Example 5 Preparation of First Agent

[0115] A first agent for virgin hair portions and a first agent foralready-colored hair portions were prepared in the same manner as inExample 1, except that the compounding proportions were changed as shownin Table 1.

Preparation of Second Agent

[0116] In accordance with the compounding proportions shown in Table 2and using 35 wt % hydrogen peroxide water, a creamy second agent havinga hydrogen peroxide content of 6% by weight and a creamy second agenthaving a hydrogen peroxide content of 3% by weight were prepared in aconventional manner.

Coloring and Evaluation

[0117] Hair, in which the virgin hair portions and the already-coloredhair portions were in the same states as those of the hair in Example 2,was subjected to coloring so as to give color tone of red type.

[0118] First, to the virgin hair portions, an oxidative hair-coloringagent (I)-5 obtained by mixing the first agent for virgin hair portionswith the second agent for virgin hair portions (hydrogen peroxidecontent: 6% by weight) in a mixing ratio of 1:2 (by weight) was applied.The oxidative hair-coloring agent (I)-5 had an ammonia concentration of0.84% by weight, a hydrogen peroxide concentration of 3.8% by weight andpH of 10.4.

[0119] Immediately after the application to the virgin hair portions, tothe already-colored hair portions, an oxidative hair-coloring agent(II)-5 obtained by mixing the first agent for already-colored hairportions with the second agent for already-colored hair portions(hydrogen peroxide content: 3% by weight) in a mixing ratio of 1:1 (byweight) was applied, followed by allowing the hair to stand for 15minutes at room temperature. The oxidative hair-coloring agent (II)-5had an ammonia concentration of 0.56% by weight, a hydrogen peroxideconcentration of 1.6% by weight and pH of 9.9.

[0120] Thereafter, the hair was sufficiently cleaned with shampoo andthen rinsed in a conventional manner.

[0121] As a result of evaluation of the colored hair by visualobservation, the virgin hair portions and the already-colored hairportions were uniformly colored in color tone of red type, and even inthe boundary portions, the same uniform color tone as in other portionscould be attained.

[0122] The results are set forth in Table 5.

Example 6 Preparation of First Agent

[0123] A first agent for virgin hair portions and a first agent foralready-colored hair portions were prepared in the same manner as inExample 1, except that the compounding proportions were changed as shownin Table 1.

Preparation of Second Agent

[0124] In accordance with the compounding proportions shown in Table 2and using 35 wt % hydrogen peroxide water, a creamy second agent havinga hydrogen peroxide content of 6% by weight and a creamy second agenthaving a hydrogen peroxide content of 3% by weight were prepared in aconventional manner.

Coloring and Evaluation

[0125] Hair, in which the virgin hair portions and the already-coloredhair portions were in the same states as those of the hair in Example 2,was subjected to coloring so as to give color tone of red type.

[0126] First, to the virgin hair portions, an oxidative hair-coloringagent (I)-6 obtained by mixing the first agent for virgin hair portionswith the second agent for virgin hair portions (hydrogen peroxidecontent: 6% by weight) in a mixing ratio of 1:1 (by weight) was applied.The oxidative hair-coloring agent (I)-6 had an ammonia concentration of1.26% by weight, a hydrogen peroxide concentration of 2.90% by weightand pH of 10.1.

[0127] After 5 minutes from the application to the virgin hair portions,to the already-colored hair portions, an oxidative hair-coloring agent(II)-5 obtained by mixing the first agent for already-colored hairportions with the second agent for already-colored hair portions(hydrogen peroxide content: 3% by weight) in a mixing ratio of 1:1 (byweight) was applied, followed by allowing the hair to stand for 15minutes at room temperature. The oxidative hair-coloring agent (II)-5had an ammonia concentration of 0.56% by weight, a hydrogen peroxideconcentration of 1.6% by weight and pH of 9.9.

[0128] Thereafter, the hair was sufficiently cleaned with shampoo andthen rinsed in a conventional manner.

[0129] As a result of evaluation of the colored hair by visualobservation, the virgin hair portions and the already-colored hairportions were uniformly colored in color tone of red type, and even inthe boundary portions, the same uniform color tone as in other portionscould be attained.

[0130] The results are set forth in Table 5.

Example 7 Preparation of First Agent

[0131] A first agent for virgin hair portions and a first agent foralready-colored hair portions were prepared in the same manner as inExample 1, except that the compounding proportions were changed as shownin Table 3.

Preparation of Second Agent

[0132] In accordance with the compounding proportions shown in Table 2and using 35 wt % hydrogen peroxide water, a creamy second agent havinga hydrogen peroxide content of 6% by weight and a creamy second agenthaving a hydrogen peroxide content of 3% by weight were prepared in aconventional manner.

Coloring and Evaluation

[0133] Hair, in which the virgin hair portions and the already-coloredhair portions were in the same states as those of the hair in Example 2,was subjected to coloring so as to give color tone of red type.

[0134] First, to the virgin hair portions, an oxidative hair-coloringagent (I)-7 obtained by mixing the first agent for virgin hair portionswith the second agent for virgin hair portions (hydrogen peroxidecontent: 6% by weight) in a mixing ratio of 1:1 (by weight) was applied.The oxidative hair-coloring agent (I)-7 had an ammonia concentration of0.84% by weight, a hydrogen peroxide concentration of 2.8% by weight andpH of 10.3.

[0135] Immediately after the application to the virgin hair portions, tothe already-colored hair portions, an oxidative hair-coloring agent(II)-7 obtained by mixing the first agent for already-colored hairportions with the second agent for already-colored hair portions(hydrogen peroxide content: 3% by weight) in a mixing ratio of 1:1 (byweight) was applied, followed by allowing the hair to stand for 1.5minutes at room temperature. The oxidative hair-coloring agent (II)-7had an ammonia concentration of 0.1% by weight, a hydrogen peroxideconcentration of 1.6% by weight and pH of 9.6.

[0136] As a result of evaluation of the colored hair by visualobservation, the boundary portions between the virgin hair portions andthe already-colored hair portions became a light zone. The virgin hairportions did not seem to have hue of red type and were slightly darkeras compared with the already-colored hair portions. The already-coloredhair portions were slightly lighter as compared with the virgin hairportions and had poor uniformity of finished color.

[0137] The results are set forth in Table 5.

Comparative Examples 1 and 2 Preparation of First Agent

[0138] First agents were prepared in the same manner as in Example 1,except that the compounding proportions were changed as shown in Table3.

Preparation of Second Agent

[0139] In accordance with the compounding proportions shown in Table 2,a creamy second agent having a hydrogen peroxide content of 6% by weightand a creamy second agent having a hydrogen peroxide content of 3% byweight were prepared in a conventional manner.

Coloring and Evaluation

[0140] Hair, in which the virgin hair portions and the already-coloredhair portions were in the same states as those of the hair in Example 1,was subjected to coloring in the following manner.

[0141] (1) An oxidative hair-coloring agent C1 obtained by mixing thefirst agent for Comparative Example 1 with the second agent forComparative Example 1 (hydrogen peroxide content: 3% by weight) in amixing ratio of 1:1 (by weight) was applied to the virgin hair portionsand the already-colored hair portions, followed by allowing the hair tostand for 20 minutes at room temperature. The subsequent operations werecarried out in the same manner as in Example 1. The oxidativehair-coloring agent C1 had an ammonia concentration of 0.1% by weight, ahydrogen peroxide concentration of 1.6% by weight and pH of 8.0.

[0142] As a result of evaluation of the colored hair by visualobservation, the boundary portions between the virgin hair portions andthe already-colored hair portions became a dark zone. The virgin hairportions had extremely lower lightness as compared with thealready-colored hair portions and did not have uniform finished color.

[0143] The results are set forth in Table 5.

[0144] (2) An oxidative hair-coloring agent C2 obtained by mixing thefirst agent for Comparative Example 2 with the second agent forComparative Example 2 (hydrogen peroxide content: 6% by weight) in amixing ratio of 1:1 (by weight) was applied to the virgin hair portionsand the already-colored hair portions, followed by allowing the hair tostand for 20 minutes at room temperature. The subsequent operations werecarried out in the same manner as in Example 1. The oxidativehair-coloring agent. C2 had an ammonia concentration of 1.0% by weight,a hydrogen peroxide concentration of 2.8% by weight and pH of. 10.0.

[0145] As a result of evaluation of the colored hair by visualobservation, the boundary portions between the virgin hair portions andthe already-colored hair portions became a light zone. The virgin hairportions had extremely higher lightness than the desired lightness anddid not have uniform finished color.

[0146] The results are set forth in Table 5. TABLE 1 First agent Ex. 1EX. 2 and Ex. 3 Ex. 4 Ex. 5 and Ex. 6 Already- Already- Already-Already- Virgin colored Virgin colored Virgin colored Virgin coloredhair hair hair hair hair hair hair hair portion portion portion portionportion portion portion portion p-Phenylene- 0.02 0.2 0.15 0.58 0.080.17 0.25 0.57 diamine Resorcin — — 0.15 0.18 0.05 0.20 — 0.25 m-Amino-— — — 0.05 — — — 0.09 phenol p-Amino- 0.5 0.25 0.015 0.05 — 0.02 0.320.54 ortho- cresol p-Amino- 0.5 0.9 — 0.24 — — 0.25 0.36 phenol Nitro- —— — — — — 0.15 0.05 paraphenyl- enediamine Cetanol 4.0 4.0 4.0 4.0 4.04.0 4.0 4.0 Liquid 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 paraffin Polyoxy- 5.05.0 5.0 5.0 5.0 5.0 5.0 5.0 ethylene stearyl ether Stearyl- 1.0 1.0 1.01.0 1.0 1.0 1.0 1.0 trimethyl- ammonium chloride Polyeth- 5.0 5.0 5.05.0 5.0 5.0 5.0 5.0 ylene glycol Sodium 0.3 0.3 0.6 0.6 0.6 0.6 0.6 0.6sulfite 28% Ammonia 11.0 4.0 9.0 4.0 6.0 1.0 9.0 4.0 water Pure water tomake up to 100

[0147] TABLE 2 Second agent Hydrogen Hydrogen peroxide peroxide content:6 wt % content: 3 wt % Cetanol 2.0 2.0 Liquid paraffin 4.0 4.0Polyoxyethylene stearyl ether 5.0 5.0 Stearyltrimethylammonium chloride1.0 1.0 Polyethylene glycol 5.0 5.0 35 wt % Hydrogen peroxide water 16.09.0 85 wt % phosphoric acid 0.1 0.1 Phenacetin 0.1 0.1 Pure water tomake up to 100

[0148] TABLE 3 First agent Ex. 7 Already- Virgin colored hair hair Comp.Comp. portion portion Ex. 1 Ex. 2 p-Phenylenediamine 0.05 0.25 0.1 0.2Resorcin 0.05 — — — m-Aminophenol 0.15 — — — p-Aminoorthocresol — 0.60.35 0.1 p-Aminophenol — 0.2 0.7 0.5 Nitro-paraphenylenediamine 0.15 — —— Cetanol 4.0 4.0 4.0 4.0 Liquid paraffin 8.0 8.0 8.0 8.0Polyoxyethylene stearyl ether 5.0 5.0 5.0 5.0 Stearyltrimethylammonium1.0 1.0 1.0 1.0 chloride Polyethylene glycol 5.0 5.0 5.0 5.0 Sodiumsulfite 0.6 0.6 0.3 0.3 28% Ammonia water 6.0 1.0 1.0 7.0 Pure water tomake up to 100

[0149] TABLE 4 Oxidative hair- coloring agent Hue (H) Lightness (V)Chroma (C) Ex. 1 (I)-1 1.5 YR 4.1 6.9 (II)-1 2.2 YR 3.3 3.9 Ex. 2 (I)-21.2 YR 3.6 1.4 (II)-2 9.8 R 1.9 1.2 Ex. 3 (I)-3 1.8 YR 4.0 1.3 (II)-39.8 R 1.9 1.2 Ex. 4 (I)-4 7.8 YR 5.3 1.6 (II)-4 1.2 YR 3.7 2.2 Ex. 5(I)-5 7.2 R 2.5 4.5 (II)-5 4.6 R 1.9 2.5 Ex. 6 (I)-6 7.6 R 2.9 4.7(II)-6 4.6 R 1.9 2.5 Ex. 7 (I)-7 8.2 YR 3.9 5.1 (II)-7 4.4 R 3.2 4.7Comp. Ex. 1 C1 1.2 YR 3.6 4.4 Comp. Ex. 2 C2 4.1 YR 4.6 2.6

[0150] TABLE 5 Ex. Ex. Ex. Ex. Ex. Ex. Ex. Comp. Comp. 1 2 3 4 5 6 7 Ex.1 Ex. 2 Results AA AA AA A AA AA A B B

INDUSTRIAL APPLICABILITY

[0151] As described above, the hair-coloring method of the invention isuseful for uniformly coloring hair having virgin hair portions andalready-colored hair portions. The hair-coloring agent set of theinvention is favorably used for the hair-coloring method and is suitablyused for barbers and beauty parlors business.

What is claimed is:
 1. A hair-coloring method comprising coloring hairhaving virgin hair portions and already-colored hair portions, wherein:(A) the virgin hair portions are colored with an oxidative hair-coloringagent (I) comprising an oxidative dye, ammonia and hydrogen peroxide andhaving an ammonia concentration of 0.2 to 3.0% by weight and a hydrogenperoxide concentration of 2.5 to 5.0% by weight, and (B) thealready-colored hair portions are colored with an oxidativehair-coloring agent (II) comprising an oxidative dye, ammonia andhydrogen peroxide and having an ammonia concentration of 0.1 to 1.5% byweight and a hydrogen peroxide concentration of 0.01 to 2.0% by weight.2. The hair-coloring-method as claimed in claim 1, wherein when thevirgin hair portions obtained by coloring with the oxidativehair-coloring agent (I) and the already-colored hair portions obtainedby coloring with the oxidative hair-coloring agent (II) are compared,these portions have almost the same hue, lightness and chroma.
 3. Thehair-coloring method as claimed in claim 1 or 2, wherein the oxidativehair-coloring agent (I) and the oxidative hair-coloring agent (II) areoxidative hair-coloring agents which satisfy at least one of thefollowing conditions when white yak hair is colored with thesehair-coloring agents for 20 minutes at room temperature; (i) thedifference of lightness (Munsell lightness) in the Munsell color systembetween the hair colored with the oxidative hair-coloring agent (I) andthe hair colored with the oxidative hair-coloring agent (II) is in therange of 0.2 to 3.0, and (ii) the difference of chroma (Munsell chroma)in the Munsell color system between the hair colored with the oxidativehair-coloring agent (I) and the hair colored with the oxidativehair-coloring agent (II) is in the range of 0.05 to 5.0.
 4. Ahair-coloring agent set comprising: (A) a hair-coloring agent for virginhair portions (an oxidative hair-coloring agent (I)), comprising anoxidative dye, ammonia and hydrogen peroxide and having an ammoniaconcentration of 0.2 to 3.0% by weight and a hydrogen peroxideconcentration of 2.5 to 5.0% by weight, and (B) a hair-coloring agentfor already-colored hair portions (an oxidative hair-coloring agent(II)), comprising an oxidative dye, ammonia and hydrogen peroxide andhaving an ammonia concentration of 0.1 to 1.5% by weight and a hydrogenperoxide concentration of 0.01 to 2.0% by weight.
 5. The hair-coloringagent set as claimed in claim 4, wherein when virgin hair portionsobtained by coloring with the hair-coloring agent for virgin hairportions and already-colored hair portions obtained by coloring with thehair-coloring agent for already-colored hair portions are compared,these portions have almost the same hue, lightness and chroma.
 6. Thehair-coloring agent set as claimed in claim 3 or 4, wherein thehair-coloring agent for virgin hair portions and the hair-coloring agentfor already-colored hair portions are oxidative hair-coloring agentswhich satisfy at least one of the following conditions when white yakhair is colored with these hair-coloring agents for 20 minutes at roomtemperature; (i) the difference of lightness (Munsell lightness) in theMunsell color system between the hair colored with the hair-coloringagent for virgin hair portions and the hair colored with thehair-coloring agent for already-colored hair portions is in the range of0.2 to 3.0, and (ii) the difference of chroma (Munsell chroma) in theMunsell color system between the hair colored with the hair-coloringagent for virgin hair portions and the hair colored with thehair-coloring agent for already-colored hair portions is in the range of0.05 to 5.0.